With this example we are going to demonstrate how to obtain a Hashtable Iterator, that is an iterator of the key value pairs of the Hashtable. In short, to obtain an iterator of the Hashtable’s entries you should:
- Create a new Hashtable.
- Populate the hashtable with elements, using
put(K key, V value)API method of Hashtable. - Invoke the
entrySet()API method of Hashtable, that returns a Set containing all the key value pairs of the Hashtable. - Obtain an Iterator over the set entries, with
iterator()API method of Set. - Invoke Iterator’s
hasNext()andnext()API methods to iterate through the set’s entries.
Let’s take a look at the code snippet that follows:
package com.javacodegeeks.snippets.core;
import java.util.Iterator;
import java.util.Hashtable;
import java.util.Set;
public class HashtableEntriesIterator {
public static void main(String[] args) {
// Create a Hashtable and populate it with elements
Hashtable hashtable = new Hashtable();
hashtable.put("key_1","value_1");
hashtable.put("key_2","value_2");
hashtable.put("key_3","value_3");
// Get a set of all the entries (key - value pairs) contained in the Hashtable
Set entrySet = hashtable.entrySet();
// Obtain an Iterator for the entries Set
Iterator it = entrySet.iterator();
// Iterate through Hashtable entries
System.out.println("Hashtable entries : ");
while(it.hasNext())
System.out.println(it.next());
}
}
Output:
Hashtable entries :
key_3=value_3
key_2=value_2
key_1=value_1
This was an example of how to obtain a Hashtable Iterator in Java.
